NGC 7023 is a beautiful emission nebula that resembles an Iris flower. The dark areas in this photograph are places where there is cold dust in space. This dust blocks the light from the stars behind it, yielding blank, dark spots in the sky.

In this image, North is Up. This image is cropped to 96% of the original full frame.

Exposure Details

Lens

Celestron C-8 SCT with Celestron focal reducer

Focal Length

1160mm (measured from the image)

Focal Ratio

f/5.8

Mount

Schaefer GEM - 7 1/2 Byers Gear

Guiding

ONAG On-Axis Guider, Lodestar autoguider, PHD Guiding

Camera

Canon 450D - Gary Honis modified

Exposure

306 subexposures of 180 seconds each at ISO 1600 - a little over 15 hours

I had photographed this object last year and had a pretty good result. However, I'm much happier with this year's version and the better edges I have from focus stacking as well as the better noise performance of the 450D over the 20Da. This is a very tricky object to process, and I may end up reprocessing it some day, as I don't think I did the best job pulling out some of the very faint out dust regions.